title: From CCSD(T)/aug-cc-pVTZ-J to CCSD(T) complete basis set limit isotropic nuclear magnetic shieldings via affordable DFT/CBS calculations.
abstract: It is shown that a linear correlation exists between nuclear shielding constants for nine small inorganic and organic molecules (N(2), CO, CO(2), NH(3), CH(4), C(2)H(2), C(2)H(4), C(2)H(6) and C(6)H(6)) calculated with 47 methods (42 DFT methods, RHF, MP2, SOPPA, SOPPA(CCSD), CCSD(T)) and the aug-cc-pVTZ-J basis set and corresponding complete basis set results, estimated from calculations with the family of polarization-consistent pcS-n basis sets. This implies that the remaining basis set error of the aug-cc-pVTZ-J basis set is very similar in DFT and CCSD(T) calculations. As the aug-cc-pVTZ-J basis set is significantly smaller, CCSD(T)/aug-cc-pVTZ-J calculations allow in combination with affordable DFT/pcS-n complete basis set calculations the prediction of nuclear shieldings at the CCSD(T) level of nearly similar accuracy as those, obtained by fitting results obtained from computationally demanding pcS-n calculations at the CCSD(T) limit. A significant saving of computational efforts can thus be achieved by scaling inexpensive CCSD(T)/aug-cc-pVTZ-J calculations of nuclear isotropic shieldings with affordable DFT complete basis set limit corrections.
authors.affiliation: Faculty of Chemistry, University of Opole, 45-052 Opole, Poland. teobaldk@yahoo.com
authors.forename: Teobald
authors.initials: T
authors.lastname: Kupka
authors.forename: Michał
authors.initials: M
authors.lastname: Stachów
authors.forename: Marzena
authors.initials: M
authors.lastname: Nieradka
authors.forename: Jakub
authors.initials: J
authors.lastname: Kaminsky
authors.forename: Tadeusz
authors.initials: T
authors.lastname: Pluta
authors.forename: Stephan P A
authors.initials: SP
authors.lastname: Sauer